The present invention relates generally to electro-muscle stimulation, and in particular to a belt-like device which is wrapped around or otherwise placed upon a portion of the body to administer adjustable levels of electrical stimulation.
Electro-muscle stimulation (EMS) is well known in the medical art. This technology utilizes a conductive pad or electrode to externally apply a very weak current to a muscle or group of muscles and thereby cause them to contract. The electrode receives an electric stimulation signal from an external voltage/current source, such as an EMS machine. The stimulation signal can be adjusted in amplitude, polarity, frequency, waveform, etc. EMS is commonly used in physical or occupational therapy to strengthen atrophied muscles or paralyzed limbs, and also to exercise muscles that are immobilized for long periods of time as a result of muscular or neurological disorders, extended periods of bed rest arising from injury, surgery, or illness. EMS is also useful for the general exercise of functional muscles to improve muscle tone and strength. For example with athletes, EMS can be used to treat muscle injuries as a supplement to conventional conditioning exercises. EMS can also be used to recondition muscles or muscle groups which have, for whatever reason, lost their tone and/or strength, have been injured, or are in need of reconditioning to effect cosmetic improvements. An operator who has been trained in the principles of EMS can analyze the areas which are of concern, and select the proper muscles to exercise and train.
For example, U.S. Pat. No. 4,480,830 illustrates a method and apparatus for exercising paralyzed muscles. The method and apparatus make use of a set of transcutaneous electrodes which are placed upon the skin of the subject over muscles which are to be stimulated. A computer controlled stimulator generates a pair of alternately pulsed stimulation signals which are applied across different pairs of stimulation electrodes to produce controlled muscle contraction. Muscle movement is resisted by a dynamic load and a position sensor provides a feedback signal indicating the movement actually achieved. The computer uses the feedback signal for modifying the control signal applied to the stimulator. U.S. Pat. No. 4,499,990 shows a system and method for treating persons with paralyzed legs. The apparatus and method include four sets of transcutaneous electrodes which are placed above the iliac and quadriceps muscles of the paralyzed person. The person is seated upon an exercycle and a series of pulsed stimulation signals are applied to the electrodes to cause coordinated contraction of the iliac and quadriceps muscles. This causes pedaling of the exercycle by the paralyzed legs. A position sensor senses the position of the pedals and transmits an indication thereof to a computer which generates control signals for stimulation driving circuits connected to the stimulation electrodes. U.S. Pat. No. 4,582,049 portrays a patient initiated response method for re-educating debilitated muscle tissue. The method comprises the detection of an electromyographic signal in a muscle group which is used to trigger an artificial stimulation signal of a higher predetermined intensity and transmit such a signal to a debilitated muscle group. The patient initiated electromyographic signal may be detected in a debilitated or non-debilitated muscle group. The operator determines the frequency and intensity of the stimulation signal. U.S. Pat. No. 4,586,495 illustrates an apparatus and method for stimulating muscular activity in an acutely injured patient. A leg which is to be stimulated is strapped into a brace and the leg muscles are stimulated to work isometrically against the brace. The effort exerted by the muscles is measured by load cells which generate feedback signals for a control computer. The computer adjusts the stimulation signals in accordance with the received feedback signals. U.S. Pat. No. 4,586,510 discloses an apparatus for exercising a paralyzed limb by functional electrical stimulation. The system utilizes simple analog devices including a reference signal generator, a position sensor, and an error signal generator. The error signal is integrated to produce a stimulation driving signal for application to the stimulation electrodes mounted on the limb. In the disclosed embodiment, the paralyzed person may be seated in an exercise chair which is equipped with a pair of loading assemblies which are attachable to the legs of the person so as to yieldingly resist the stimulated movement. U.S. Pat. No. 4,724,842 shows a method and apparatus for muscle stimulation. An exercise machine or dynamometer is provided with control apparatus for ascertaining the physical position of a patient during an exercise. The patient is then electrically stimulated over selected ranges of motion in order to aid in the exercise. U.S. Pat. No. 4,785,813 consists of an apparatus for assisting muscular contraction of a partially paralyzed muscle. The system uses a pair of electrode terminals which sense voluntary EMG signals at the site of the muscle and periodically transmit appropriately corresponding higher level stimulation signals. Stimulation signals are generated by a pulsed stimulator operating under control of an amplifier arrangement connected to receive the EMG signals from the electrode terminals. A transistor switch interrupts the amplifier output in synchronism with the generation of stimulation signals. U.S. Pat. No. 4,838,272 describes a method and apparatus for adaptive closed loop electrical stimulation of muscles. The method and apparatus strengthens skeletal muscles through maximizing muscle tension in which electrical stimulation signals are applied to the selected muscles at a predetermined frequency, pulse width, and amplitude, and work output by the muscles in response to stimulation signals is determined over a fixed period of time. The work output is compared to a defined value which can be a target value or a value measured during a previous stimulation period. U.S. Pat. No. 5,070,873 includes a method of and apparatus for electrically stimulating quadriceps muscles of an upper motor unit paraplegic. Muscle fatigue of an electrically stimulated quadriceps muscle of an upper motor neuron paraplegic is detected and compensated for by monitoring the myoelectric (EMG) signal produced by the stimulated muscle and controlling one or more of the following parameters of the electrical stimulation (ES) signal: pulse repetition rate, amplitude, and pulse width. U.S. Pat. No. 5,330,516 depicts a device for generating hand function having an S-type splint consisting of a forearm portion extending along the palmar side of the forearm, a palmo-dorsal transition portion leading to a dorsal portion extending across the dorsal side of the carpal bones of the hand, and a palmar portion which touches the palm of the hand of the wearer of the device at least indirectly. A plurality of electrodes are mounted on the splint in positions in which they can make contact with skin portions directly overlying the muscles to be stimulated. U.S. Pat. No. 5,507,788 illustrates a method and apparatus for controlling skeletal muscle fatigue during electrical stimulation. Electrical stimulation signals are applied to muscles at a frequency which is varied in response to a detected ripple signal in an output tension or torque record which corresponds to the fusion of the multiple muscle contractions. An average torque amplitude is first determined when a stimulation signal is applied at an initial frequency. The amplitude of the ripple on the torque output is then determined and compared to the average torque amplitude to provide a ripple percentage. The measured ripple percentage is compared to a selected ripple percentage corresponding to the desired fusion of the multiple muscle contractions. And the stimulation frequency is adjusted by a feedback loop until the measured ripple percentage conforms to the selected value. U.S. Pat. No. 5,628,722 shows a method for maintaining knee stability of a user suffering from damage to a knee ligament. The method includes a sensor feedback system for measuring abnormal physical relationships between the tibia and femur. The sensor feedback system determines whether selected conditions have been met warranting the application of electrical stimulation and provides information regarding the determination to an electronic stimulator. Electrodes are spaceably mounted on the hamstring and/or quadriceps muscles in electrical communication with the electronic stimulator for causing contraction of the thigh muscles at selected levels, thus providing a posteriorly and/or anteriorly directed force to the upper tibial bone and thereby preventing its instability.
The present invention is directed to a device for administrating electro-muscle stimulation (EMS) which comprises a flexible covering containing positionable electrodes which are strategically placed upon a patient""s body to stimulate specific muscles or muscle groups. In a preferred embodiment, the covering is in the form of a belt or band which is snugly wrapped around a portion of the patient""s body. The belt is typically used in conjunction with an EMS machine which emits an electrical voltage/current for activating the electrodes. The electrodes in turn cause the selected muscles to contract. By placing the electrodes in specific locations within the belt, and correlating these sites over targeted muscles, contraction of the desired muscles is made possible. The present invention also provides means for stimulating muscles that are otherwise difficult to exert, and furthermore causes muscles to contract further than would be the case with normal exercise or usual muscle contraction. The present invention may be used to augment and enhance natural exercise to encourage maximum muscle contraction, and can significantly extend the duration of an exercise period. Controls are provided allowing a user to establish the level of stimulation, and to adjust or xe2x80x9ctunexe2x80x9d the level of stimulation applied to specific muscle or muscle group sites.
In one preferred embodiment, the present invention comprises an xe2x80x9cextremity cuffxe2x80x9d which is useful in stimulating muscles in the legs and arms. The electrodes are placed in a line along the length of the cuff, and may be longitudinally positioned to accommodate the stimulation of specific muscles. Also in a preferred embodiment, two cuffs are simultaneously utilized, with one cuff containing positive electrodes and the other cuff containing the negative or return electrodes. It is noted that both positive and negative (return or common) electrodes are required in order to develop a stimulation current flow. Each electrode has a stimulation level control. In this manner, each electrode can be individually adjusted, and is thereby capable of varying the stimulation intensity at a targeted muscle or muscle group.
For the purpose of easy handling, the two cuffs may be abutted together with the use of a hook and loop attachment means such as sold under the trademark Velcro(copyright), and thereby serve as one intact unit. Alternatively, the positive and negative cuffs may be separated from each other along the length of a muscle, such as at the opposite ends of a thigh. For more versatility, each cuff may be rotated around the extremity for fine adjustment. The cuff also has a Velcro synching belt so that pressure is applied to force the electrodes into close contact with the skin of the patient, thereby enhancing the conduction of the stimulation signal. The electrodes and cuff are composed of a pliable material, so that they conform around the circumference of the arm or leg being stimulated. Also, the cuff may be made of an elastic material to allow stretching. By stretching the cuff, the electrodes may be relocated or selectively positioned to ensure proper placement with respect to the site being stimulated. Or electrodes within the cuff may be relocated or selectively positioned. In addition, the elastic material provides flexibility so the muscles can contract and relax without displacing the electrodes.
Extra electrodes on each end of the cuff provide the capability of adjusting the length span of the electrical stimuli. This is useful in that the length of the cuff, active with electrical stimuli, may be adjusted to fit different extremity circumferences. Electrodes on each end of the cuff may be turned off or on, allowing the cuff to adjust for different sizes of extremity girth.
A unique feature of the cuff having multiple adjustable electrodes is that the user may stimulate specific portions of a muscle group differently from other portions. This becomes especially useful in correcting muscular imbalances as seen in patients after muscular injuries, surgeries, strokes, or biomechanical dysfunctions. For instance, a muscle group such as the quadriceps often does not become uniformly deficient. Either the medial portion or the lateral portion will become more deficient over the other. Therefore, it is imperative that certain sections be developed over others to restore normal function. As an example, a deranged patella (kneecap) that is laterally displaced does not properly track over the femoral surface or groove. As the knee is extended and flexed, the patella improperly rides over the lateral crest of the femoral groove creating pain. Ultimately degenerative changes occur. In these instances, it is necessary to develop the medial portion of the quadriceps over the lateral to correct the problem. This development may be accomplished with the use of the present invention.
In another preferred embodiment, the present invention comprises an abdominal belt with three specific channels which are strategically bilaterally placed to contact the lower portions of the abdominus rectus, the upper portions of the abdominus rectus, and the obliques on both sides. A master control determines the overall stimulation intensity of all electrodes, and separate individual controls determine the stimulation intensity of each electrode. The most significant advantage of the separate controls is to allow the user to decide where to place the most emphasis. For example, by delivering higher voltage to the lower portions of the rectus abdominus and the obliques, they may be stimulated more than the upper portions of the rectus abdominal which are easier to exercise. The belt is made of an elastic pliable material to allow mobility of the body of the user. This provides the option for a person to exercise concurrent with the electrical surge.
The abdominal belt has one positive electrode located over the upper portions of the rectus abdominus, one positive electrode located over the lower portions of the rectus abdominus, and a negative or return electrode located in the umbilical region. By sharing one common electrode, elimination of one negative or return electrode is made possible. When the upper rectus abdominus electrode is solely activated, muscle contraction occurs between the upper portions of the abdominus rectus and the umbilical region. Conversely, when the lower rectus abdominus electrode is solely activated, muscle contraction occurs between the lower portions of the abdominus rectus and the umbilical region. When the upper and lower rectus abdominus electrodes are simultaneously activated, the electrode at the umbilical region serves as the negative or return electrode for both the upper and lower rectus abdominus electrodes. Consequently, there tends to be a higher electrical stimulation intensity at this region. However, this is a favorable phenomena since the umbilical region tends to have a thicker layer of fatty tissue. A higher level of stimulation intensity is required to penetrate the layer of fat in order to stimulate the underlying muscle wall. Additionally, higher levels of stimuli cause stronger muscular contractions and greater toning results.
Although the upper and lower portion of the abdominals comprise predominately the same muscle, rectus abdominus, it is important to separate them into two portions with respective and distinctive electrical stimulus controls. The upper portions of the rectus abdominus require less electrical stimulus because of their increased sensitivity due to decreased thickness and proximity to the underlying sternum and ribs. Additionally, the upper portions of the rectus abdominus are easier to exert with normal exercise than the lower portions of the rectus abdominus, thereby usually requiring less emphasis.
The shape of the electrode for the lower portions of the rectus abdominus is in the form of an truncated xe2x80x9cVxe2x80x9d, with the apex toward the pubes. This configuration avoids stimulation of the femoral nerve at the inquinal area, and the undesired sensation along the femoral nerve into the leg. Alternatively, an insulative pad may be placed over the inguinal area to avoid stimulation of the femoral nerve.
Each group of oblique muscles, right and left, has its own set of positive and negative electrodes. The placement of these electrodes is adjustable to accommodate differences in anatomical make up and waist size. The negative electrode is placed toward the midline adjacent the negative electrode for the rectus abdominus in the umbilical region to minimize interference between the operation of the electrodes for the different muscles. Since current will take the shortest route between opposing poles or electrodes, the electrical stimulation intensity of each oblique is isolated from the other and will not affect the electrical stimulation intensity to the rectus abdominus. Similarly, the electrical stimulation intensity to the rectus abdominus will not affect the obliques. Proper placement of opposing electrodes is important. It enables controlling the pathway of electrical stimulus, either promoting stimulus along the bodies of specific muscles, or avoiding stimulus over undesired areas, such as the femoral nerve and ovaries.
Additionally, the negative electrodes of the obliques are placed at the junction of the rectus abdominus and external obliques. This area is especially rich with motor points. Motor points are areas that are reactive to stimuli, requiring less electrical intensity. Further, development of this area has the aesthetic property of enhancing definition making the differential between the abdominus rectus and the obliques more pronounced.
It is biomedically important to stimulate the right and left oblique muscles equally to achieve equal muscular development. Imbalances in muscular development may lead to musculoskeletal problems. Since the obliques are on opposite sides of the abdomen, each side requires its own set of electrodes which makes it more difficult to achieve equal stimulation. Numerous factors make equal stimulation difficult. The placement of the electrodes over the muscle with respect to the right and left side is important. One side may be more favorably placed over motor points or muscle fibers than the other, causing a stronger contraction. Conduction between the electrodes and the skin is another factor which determines the strength of muscular contractions. Conduction properties are influenced by the amount of moisture or conducting gel on the electrodes and the amount of pressure forcing the electrode against the skin. All of these factors make it necessary to incorporate a balance adjustment component to divert electrical stimulus to one side or the other in order to obtain equally balanced muscular contraction of the left and right obliques. In contrast, the left and right rectus abdominus are butted so close to each other that they are much more likely to contract equally and may share the same electrodes. A balance control at this site is therefore not necessary.
Typically abdominal exercises are divided into three areas of concentration: the upper portions of the rectus abdominus, the lower portion of the rectus abdominus, and the right and left obliques. For each of these areas specific exercises are performed to put special emphasis on the area. For example, stomach crunches with knee bends are used for the upper portions of the rectus abdominus, hip thrusts or straight leg crunches are used for the lower portions of the rectus abdominus, and oblique crunches or side crunches are used for the obliques.
In actuality, it is impossible to solely separate muscular action of any of these groups from each other. They all contract simultaneously to some extent when any one is stimulated. The exercises cited above merely apply heavier emphasis on one area over the others. However, applying emphasis to specific areas is required to achieve favorable results in the long run. For example, it is more difficult to exercise the obliques and lower portions of the rectus abdominus that it is to exercise the upper portion of the rectus abdominus. Consequently, the obliques and lower portions of the rectus abdominus are often neglected and become problem areas. The present invention enables direct emphasis on any of the aforementioned areas, or any combination of intensities to any of the areas as desired. This allows versatility in the targeting of problem areas without the necessity for specific exercises for the problem areas.
The versatility of the present invention lends itself to the fact that everyone has different builds and different needs. For example, women after child birth lose tonicity in the lower portions of the rectus abdominus and develop a pelvic pouch. Obviously, in this case it is more desirable to emphasize the lower portions of the rectus abdominus. Men tend to develop love handles. More emphasis should then be placed on the oblique muscles. In each of these cases, the specific exercises for these problem areas can be extremely difficult to perform and people often just lose hope and do nothing. The present invention allows them to exercise these areas easily.
The embodiments of the present invention may obtain their electrical power from a conventional electrical muscle stimulation (EMS) machine used in physical therapy applications, or may be powered by a portable battery type unit.
The belt may be used either passively or actively. In the passive capacity, the user exerts no activity and the electrodes artificially stimulate the muscles. In this passive state, the EMS machine controls all muscular contractions by automatically emitting electrical surges. The surges may be adjusted to suit the needs of the user. The EMS machine has controls that adjust the amplitude of the surge, the duration of the surge, and the rest period between each surge. The belt may also be used in an active capacity in which it is used to augment exercise. In this aspect the belt directs and targets muscle groups as determined by the user while simultaneously exercising. For example, the output of the EMS machine may be adjusted automatically by a potentiometer attached and moved by the exercise equipment utilized by the person.
Another advantage of the present invention is that it is cost effective. Typically, when numerous electrodes are placed at different sites on the body, more sophisticated EMS machines are used. In order to control the intensity of each electrode, the EMS machine requires a separate outlet channel for each set of electrodes. The cost of an EMS machine drastically increases with an increase in the number of output channels due to the increased circuitry required to produce each stimulation signal. Conversely, the present invention splits the electrical current and only one outlet channel is required in the EMS machine. The electrical components are far less extensive in the present invention, thereby resulting in a more cost effective device.
In accordance with a preferred embodiment of the invention, a device for administrating electro-muscle stimulation (EMS) includes a flexible covering having a plurality of spaced apart electrodes. In a preferred embodiment the flexible covering is shaped like a band or belt, and is designed to encircle and be snugly connected around a portion of a patient""s body.
In accordance with an important aspect of the invention, the band or belt is fabricated from an elastic material so that the electrodes are pressed against the skin of the patient allowing the locations of the electrodes to be adjusted.
In accordance with an important feature of the invention, the band or belt is made in a plurality of sizes to fit different size persons and different portions of the body.
In accordance with another important aspect of the invention, the electrodes are selectively positionable to different locations on the flexible covering or band, so that they may be placed directly over a selected muscle or muscle group.
In accordance with another important feature of the invention, each electrode has its individual control for adjusting the level of the electrical stimulation signal, so (1) that different muscles can receive different levels of stimulation, and (2) the level of stimulation may be changed during the course of treatment.
In accordance with another important aspect of the invention, a master adjustment control is used to adjust the stimulation signal level applied to all electrodes.
In accordance with another important feature of the invention, the individual adjustment controls are located adjacent their respective electrodes on the flexible covering or band.
In accordance with an important aspect of the invention, the electrodes are placed in a pattern which matches predetermined groups of muscles, the muscles being the upper portions of the rectus abdominus, the lower portions of the rectus abdominus, and the obliques.
In accordance with an important feature of the invention, the electrodes receive either a positive or negative stimulation signal, and are positioned upon the flexible covering or band so that stimulation interaction between different muscle groups is minimized.
In accordance with an aspect of the invention, the electrode which stimulates the lower rectus abdominus, is shaped so as to avoid stimulation of the femoral nerve.
In accordance with another preferred embodiment, a return electrode is positioned between two positive electrodes. The voltage to the two positive electrodes is controllable so that as the voltage to one is increased, the voltage to the other is decreased, and visa versa.
In accordance with another preferred embodiment of the invention, the flexible covering is folded to form a pocket, and a sponge assembly is removably inserted into the pocket. The sponge assembly contains a plurality of removable sponges.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.